Network test devices test the functionality of network devices, such as routers, switches, firewalls, and network address translators, by sending test packets to the network devices and monitoring the responses. For example, in order to test whether the routing tables of a router are properly configured, a network test device may generate packets, send the packets to the router, and monitor one or more output ports of the router to determine whether the packets are routed to the proper destinations. In a load testing scenario, the network test device may send packets to the router at a high data rate to see how the router's performance is affected by increased traffic loads.
In these and other test scenarios, it is desirable for the network test device to detect lost and misdirected packets. Misdirected test packets are test packets that are transmitted to the device under test that are received by the network test device at a port other than the expected receive port of the device under test. Lost packets are test packets that are transmitted to the device under test but that are not returned to the network test device. Packets may be lost or misdirected for a variety of reasons, including misconfiguration of the device under test, misconfiguration of the test setup, hardware or software defects in the device under test, etc. For both lost and misdirected packets, it is desirable to provide the test system operator with as much information as possible so that the operator can determine the cause of lost and misdirected packets.
Accordingly, in light of these difficulties, a need exists for improved methods, systems, and computer readable media for misdirected packet drill down and negative packet capture at a network test device.